Re: What are invisible frames for?

[Michael Welsh Duggan <mwd@md5i.com>]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> In src/frame.c, the notion of an @dfn{invisible frame} is implemented.
>> On a GUI, when a frame is in this invisible state, it appears to be
>> completely inaccessible to the user - it doesn't appear anywhere on the
>> GUI, there appear to be no commands to access it, and so on.  Only a
>> Lisp form can do anything with it, like making it visible again.
>>
>> What is this facility used for?
>
> I don't know what was it's original intention, but I know it's used in
> `server-select-display` (via the frame property `visibility`) to create
> a dummy frame that lets us "select a display" without having to select
> any of its "real" frames (because it doesn't have any yet).
>
> I have the impression that I've used it elsewhere in a similar
> "hackish" way but can neither remember where nor why.  And maybe I'm
> just misremembering.

I know that "emacs --daemon" creates a frame that isn't displayed.  I
don't know if that frame is an "invisible frame" by this definition, but
I thought I'd mention it, just in case.

-- 
Michael Welsh Duggan
(md5i@md5i.com)